Hey mate,
First off, it's a great lens. I've got the same one and absolutely love it.
I see you have some similar focal length lenses in your kit, so I'm assuming you're used to taking photos around 200mm. If not, probably a bit of practice beforehand would be a good idea.
I haven't been to the Sydney event, but from what I can see on TV it looks like there are fences everywhere (same as Gold Coast, F1 Melbourne etc). Do some walking around the track. You either want to find a spot where the fence isn't in your way (almost impossible where i've been)
OR
a spot where you are as close to the fence as possible, and the cars are far enough away that you can shoot at around that 200mm.
You're then going to be shooting through the fence. To do this, you want your aperture fairly wide ( 2.8 ) to blur the fence out. You also want a slower shutter speed to show some movement, at least in the wheels. Somewhere around 1/200 is a good starting point. If it's a nice sunny day, you're not going to be able to shoot at 200 & 2.8... so, it's a bit of a balancing act between slower speeds, and blurring out the fence. Check your shots as you go.
If you can find a spot where the fence is in the shade, and the cars are in the sunlight, that will also help get rid of the fence from your shots.
As for specific lens settings, you'll see a bunch of switches on the side. The top one is minimum focus distance of the lens. I would typically set this at 2.5m at the track, to minimise the camera focusing on the fence itself.
AF/MF - set to AF. (for me anyway)
Stabilizer - ON (this will help if you are using slower shutter speeds)
Stabilizer Mode - 2 (this only corrects for up and down movements, but not side to side, so you can get nice panning shots)
Hope this is all of some use to you. Apologies if there are things here you already know. I'm by no means an expert, these are just things that work for me.
Feel free to ask any other questions if you have any though.
Also, here is an example of what can be achieved through the fence. I took this one at the Gold Coast, the fence was about a metre at least away from me, but in the shade.

7D | 40D | 17-55 2.8 IS | 70-200 L 2.8 IS | 100-400 L | 580EX II | 430EX II | 1.4x Extender