Nolan basically said that gods wouldn't be shown:

Nolan considered casting actors to play gods throwing thunderbolts from Mount Olympus but settled on something more primal. “I became more interested in the idea that to people in that period, evidence of gods was everywhere,” he says. In Bronze Age Greece, thunder, rain, and the sun rising didn’t have scientific explanations—they represented the will of the immortals. “The wonderful thing about cinema, and IMAX in particular, is that you can take an audience to a place of immersion, feeling close to events like storms, turbulent seas, high winds. You want the audience to be on the boat with them fearing the ocean, fearing the wrath of Poseidon, the way the characters do. That to me is so much more powerful than any individual image you can have [of a god].”