The slightly scruffy plumage and a flash of red on the tail but not on the head makes me think it is a juvenile red-shafted flicker - do you happen to be in the west of North America? - so it may not have quite figured out what a tree is yet.
First, you'll want to repair the damage and re-paint. Take the opportunity to check for insect boreholes as that will need to be taken care of too.
Then, various sites, e.g. www.birds.cornell.edu and There is a woodpecker pecking on my house! Why is it doing that? How can I make it stop?, recommend plastic netting to cover the area in question.
Other methods are suggested, but I would think that black netting would be aesthetically the least intrusive unless you want to go to the effort of applying aluminium sheet and painting that to match.
It might be that scaring it off every time you see it would suffice to put it off returning, but you're going to have to get up there to repair the damage anyway, if only to deter carpenter bees and such.