If it's just the paint/colorcoat that's damaged, get a spray can of white epoxy enamel paint that matches the white of your board (Here's a link, but it does not list the Pantone of the white used on your board)
Mask off the damaged area and sand it slightly to remove anything loose. Give it a couple of light coats of paint and then lightly sand it back for a nice looking repair.
If your damaged area is greater, check out the "Damage Repair" pages at this link:
Hope this helps,