Supervisor has said some very disgusting things online, should I pull my name from our paper?

I don't think you need to pull your name from the paper(s). You're junior enough, and there are enough odious high-ranking people spouting nonsense online, that people won't blame you.

I WOULD start looking for more mentors ASAP. You need stronger letters of recommendation, as some people are going to question his judgement and ability to objectively evaluate you. Also, this guy clearly has done a bad job managing his professional image, which means he might have bad judgement about professionalism in general. If you learn professional norms from him, this might do damage to your development as a researcher. This is red flag land, and the sooner you can disentangle yourself the better.

The other answers here (at the moment: Well..., Arno, and Libor) give good advice that it is unnecessary for you to withdraw from the paper in most cases.

But there is an exception to this. If the nature of the research is such that the misinformed opinions of this person can affect the results, then you can have little confidence that the overall result is valid. And since you were mostly involved with technical issues, not the driving ideas of the paper, you should consider this.

There have been people in both CS, William Shockley, and mathematics, Robert Lee Moore, who held terribly racist views, but whose scientific work was independent of those views. In a case like that you should almost certainly leave your name, since the work is done. But I would probably disassociate myself from them in future.

But if the field is closely related to those views, then it is much more problematic to be associated with them. But it is the views that you need to disassociate from, not necessarily the person. (But who needs the grief?) You don't have a choice in your crazy uncles, but you do have a choice in your colleagues.

While I strongly feel that people like this should be ostracized, I think the onus is on their instituations and peers - not on undergraduates. Very few people would blame you for having worked with your supervisor, and should you ever be accosted for it, you can truthfully point out that you embarked on the research internship before learning of his repugnant views.

From a purely pragmatic perspective, having this conference paper on your CV will do more than enough for your grad school applications to outweigh the risk of your reputation being tarnished by association here.

If you feel that you need to do something about the situation, my suggestion would be to signal your own views in other ways. For example, if your university has something like a gay-straight-student alliance, volunteering there and putting this on your CV should get you ahead of any unfortunate associations. Again, I don't think you need to do anything, neither from an ethical nor pragmative perspective.