Does swimming build muscle

I would say any exercise will eventually build muscle. In the case of swimming, muscles will be strengthened, and therefore built all over the body, but not to the point of being massive, depending on how much swimming is done on a regular basis. If swimming is done regularly, muscles will be toned and any excess weight lost. The whole body is used for buoyancy and movement during swimming and is an Excellent all over exercise. Heart muscle and lungs will strengthen too. Respiration will become more even and have a positive effect all over the body.
Most exercises will build muscles. Swimming will help build muscles but if will not be the most aesthetically obvious for quite a while if that is your aim.