In general, the biggest payouts will come from exotic wagers, which require you to pick not only the winner of the race but also the top finishers. For example, here were the payouts for the exotic wagers at the 2019 Kentucky Derby:
Exacta: $3,009.60
Trifecta: $5,737.65
Superfecta: $51,400.10
While the payouts were huge on these wagers that year, remember that it was a longshot that won the race and that these bets can be tough to hit.