If you are wanting to name it with respect to styrene, then what you have is fine! I don't think anyone would misunderstanding it. That being said....
Here's how I would do it:
1. Pick of substituent, call it the origin. This will go at the end of the name.
2. Count around to the next lowest moiety (I find that people like to count clockwise, regardless. Makes things easier, I suppose.)
3. Rinse, wash, repeat; throw the name of the base structure at the end.
1-fluoro-3-methyl-5-vinylbenzene
(with or without space: vinyl_benzene)