If the generator is propane .. I would use a lattice screen or a. Screen that pleases you paint it to blend ... it should be open ..splits or openings
Then a good distance away, plant to visually conceal the lattice if you dont like it
Dont plant anything with big roots that could compromise the gas line
And the generator vents when it runs and a " wall" of plantings could keep the gas from disbursing and maybe even send toward house .. that looks like a window right behind it.. it would get that exhaust
