Do this from the console: The way I assume you're lookin' for is to type "/cg_draw fps" or "/cg_show fps" (no quotes).
I should note that these could be wrong. They haven't worked for me, but you might want to check The Guru of 3D to be sure. I'm not a real Quake 3 fan and I only use it for benchmarking, so take it with a grain of salt.
correct me if i iz wrong - but aint the console the place where you type in cheats like god and stuff?