saving output as .eps

You can use latex rather than pdflatex then

dvips -E ...

will try to generate an EPS file from the resulting dvi.

Alternatively use pdflatex then there are several tools available to convert pdf to EPS (almost all wrappers around ghostscript) imagemagic convert for example.

You can also generate the pdf file first, then convert it to eps file in command line

pdftops -eps filename.pdf

If you get

-bash: pdftops: command not found

install poppler with

brew update
brew install poppler