If there is a cable and jack standard for I2C?

I2C specification does not specify any connector, as it is not a specification for an external interface. Many technologies that are based on I2C do specify a connector and pinout for an external interface, for example Access.bus has 4-pin connector. Lego Mindstorms also implements I2C over 6P6C connectors.

See Access.bus, a form of I2C designed for low-speed desktop devices with hot-plug capability. Unfortunately, it was quickly overshadowed by USB, which came out shortly afterward.