It is really hard to say if exactly the Voyager 1/Cassini mission was a direct inspiration for the film's visuals of Saturn and clear statements on this are hard to find. However, what is very apparent is that

actual space footage in general had a big influence on the film.

It is known that beyond using the same IMAX cameras that actually were out in space recording real NASA footage, Nolan also consulted with space-filmmaking experts and watched many a real NASA documentary recorded in space, as explained in this Space.com article and the accompanying featurette from IMAX.

Nolan and his team watched hours of IMAX footage recorded in orbit, to get familiar with what life in space should look like. Because of IMAX's long history with the NASA shuttles, Nolan's team didn't have to imagine what the space scenes should look like: they had the real thing right in front of them.

So it is no surprise that they tried to mimick the visual impression of space on camera as accurately as possible, including the apparent lack of stars, the unusual but physically accurate appearance of a black hole, or the immitation of real rocket launch footage. In fact this lack of stars and the general ambition to accurately replicate real space footage might be a major contributor to your impression about the direct reference of Cassini imagery, even if that might not have been deliberately intended by the filmmakers. Afterall, Saturn with its rings makes for a visually stunning and interesting location in general.