I don't think that's how it works.
Didn't Einstein show that gravity is a curvature of spacetime?
Assuming that gravitons are real, how would they work anyway? Do they move from one place to another? At what speed? Do they pass through baryonic matter without interacting or do they interact? If they don't interact, what explains the force of gravity that we observe? If they do, how does it work? They come from the sun, but they pull, not push? Do they impart some sort of negative momentum? Do they have mass or are they massless?
To me, curvature of spacetime is a much simpler way to think about gravity. If it's particles, I have a hard time even picturing a mechanism by how they would work in the way we observe gravity.