This is why you should have read the manual, especially for an unusual motherboard like that. It states that the power connector pinout is proprietary, you will either need to get a compatible PSU from Supermicro or try and build some sort of adapter based on the information in the manual (Page 2-26), take care with what you are doing as you are at risk of damaging something if you do it wrong. Alternatively you may be better off selling/returning the motherboard again and then buy a more standardised motherboard.