Omnipresence you are everywhere throughout all of space and time all at once always. Absolute speed you can move so fast that speed loses its meaning, but you’re still not everywhere at once even if it can seem like you’re in multiple places at once with how fast you move

Essentially, in a race a person with absolute speed would, no matter how fast they were able to run, always find the person with omnipresence was there before them, mainly because the person with omnipresence is already there before the race even started

I think a perfect example of absolute speed is that you would always be faster than everyone to the point not even the most fastest speedsters could outrun you

Omnipresence: You're already at the location.

Absolute Speed, you still need to move to that location no matter what speed you're going.