Are you putting the key switch to the "P" position when switching off the bike?
How old is the battery and what type is it, flooded or AGM?
Do you have any accessories on the bike which could drain the battery?
Start unplugging random electrical connectors, eventually one will make a difference, you can track it down from there. Divide and conquer. A voltmeter set to amperage between the positive post and positive cable can measure the parasitic draw, you can use that while diagnosing.