Might the universe have had a cause? Sure. Is there any reason to think the universe is required to have had a cause? Not really. If causality is a property of the universe, it's a bit silly to talk about causality requiring a cause. It's also possible the universe in some form has always existed. In essence, there's no excuse for a hypothetical god not requiring a cause that couldn't also be applied to the universe. In fact, it might be fair to say the universe has always existed when time as we know it exists a finite amount backwards, but that's a matter of semantics.
If the universe did have a cause, there's no reason to think it wasn't a natural cause. Perhaps the natural cause to the universe has always existed in some form. Perhaps the cause is atemporal. Perhaps it's a causal loop of the universe in a future state causing the universe in a past state (e.g. something natural, or Stewie Griffin's time pad exploding and causing the Big Bang). We just don't know, and absence of an explanation is never a reason to believe another explanation.