In my experience, it makes no difference to a domestic cat whether it is dark or light when they sleep.
Habitually, they will sleep during the daytime when it is light because domestic cats are programmed to be active at dawn and dusk and at night time in general. Although today’s domestic cats can be active at any time as they adapt to living with humans. But I would state that in general the domestic cat sleeps more often during daytime when it is light. This is not because they prefer it, it is simply a consequence of their biological clock.
Having observed domestic cats for a very long time I do not see any preferences in respect of sleeping when it is light or dark although there will be a natural threshold where it is too light to sleep comfortably. Cats may seek out hiding places to snooze or sleep but this is more likely to do with a feeling of security rather than the ambient lighting conditions.
My experience with domestic cats tells me that domestic cats can sleep well under light or dark conditions and that they have no particular preference. They don’t seem to seek out dark places to sleep. My cat sleeps under the covers with me in bed at night and on his cat condo at the window in the daytime. The former is pitch black almost and the latter is quite light. I think my cat is very typical of all domestic cats. Indeed, sometimes he will sleep on my lap while I read a newspaper and there is a reading light projected onto the newspaper and onto him. I try and shield him from the light but it doesn’t concern him.
Domestic cats are more flexible than humans in this regard as humans nearly always follow of fixed pattern of being active during the day and sleeping at night.
Lions generally hunt at night and therefore sleep when it is light. In fact the majority of wild cat species are nighttime or crepuscular hunters and therefore will rest and sleep when it is light.
However, I would welcome input from other cat owners on this matter. The reason why I have written this short post on the subject is because Google tells me that web surfers ask the question in the title and therefore it should be answered.