Dred's answer will be "on a laptop".

Hah! I was actually going to post that when I saw the thread title.
Unfortunately, no one seems to bet on GP races, so a sports book won't have it up. Honestly Id try going to the Yard House on LV Blvd south (south of Mandaly by a mile or so). Good food, beer of course, lotsa TVs - call ahead and see if they'd change the channel for you.
Edit - like Blunder said, if you're placing a bet they'll change the channel for you. Just not sure how the oddsmakers handicap a moto race, or if they even have the knowledge. Bellagio has a nice one, though.