I am travelling with my co-worker, can I apply for his visa on his behalf? Also what exactly am I required to bring?

yes, you can apply for his visa on his behalf, you need to bring the below documents:
(1) An original copy of passport with enough blank visa pages, valid for at least another 6 months.

(2) A fully completed copy of Visa Application Form V.2011A signed by the actual applicant;

(3) One recent 2×2(in.)-sized color passport photo, white in background, with a full front view of the applicant's head and shoulders but without any head cover.

(4) Round-trip flight tickets and hotel booking (if available)