Frank beat me to it. He can type faster than me lol.No idea what you have for tools or machines, but to lay them out by hand you could:
-clamp the shaft in a pair of V-blocks, set on surface plate, and scribe each end at half the diameter using a height gauge or surface gauge on the plate.
-scribe the desired radius, punch to mark, and drill the four holes (two on each end)
-take two close fitting pins and stick them into the holes on one end of the shaft
-return to the v-blocks and surface plate, but instead of orienting the pins horizontally like before, bring them up against the edge of a square so that they're now at 90 degrees vertical (six o clock and twelve o clock)
-take the height gauge that you used before, scribe both ends again at half height of the shaft and mark as before.
All you've done is scribe two horizontals on the first setup, and then using a couple of pins as registers to butt up against a known square you've oriented the piece at ninety-degrees so that you can mark two more horizontals for the second set of holes.
Let's see what other methods come in, there's quite a few ways to skin this cat.
I like this one, but you could take it a little futher by finishing one end then bolt a square to the finished end and stand it up in a mill vice and locate the holes on the other end.Drill your 4 holes in one side and use 2 pins to locate your second side . That is assuming that your ends are square .