Yeah you're shooting at f5.6 @ 200mm. For the brightness of your image, try increasing your ISO to about 400 (in this instance). The other option would be longer shutter but that's inadvisable with a moving subject. That's also where the vignetting is coming from. For something like that, zoom all the way in, get your comp, and then zoom back out some. That way you can crop it down in post if you can't correct the distortion.View attachment 2151204
Maybe a little dark?
Edit: I think it's a little dark because of the max focal length on the zoom. It's not just the best and the greatest😊
Nikon D40X - 55-200 mm
200 mm, f/5.6, iso 100, 1/1000s