Rest it for a while and do ice it often. Tape the ankle to stabilize it from moving left or right, during rolling, when you come back of course. For a while, let your opponent know of your injury so they are careful, then be ready to tap with lightning speed if anything around that ankle gets threatened.
The above is when you want to come back quickly and rehab while not missing jiu jitsu. This is what I do but I don't think everyone is capable of this. If you really want the safe route, Brandon had a good suggestion to me: PRICE: Pressure, Rest, Ice, Compress, Elevation. I think this is correct. Most important of these is ice, and don't forget Advil to aid in stopping the swelling. This could be your chance to rep techniques over grappling.