Since the letters "MC" are stamped on the ID ring along with the other information I would think it is a Minolta MC/MD mount lens. Even if the "MC" stand for "multi-Coated" and was printed on the lens for all of the various mounts for which it was made, the "MC" led me to compare it to the Minolta mount.
The bayonets match up with the Minolta pattern as does the "notch" in the bayonet opposite the aperture linkage lever. The only difference between the photo in the OP and the photo of a Minolta MD mount lens below is the direction in which the lens is oriented. They're both the same mount.
