Hi hope you've sorted this out by now but if not this video should help, it's a different audio interface but it all works the same regardless!
Before you do that make sure you've downloaded the latest drivers for your interface, you will then have a new option in the Audio device drop down list in the audio settings for Studio One. Make sure you selected your specific audio device in the audio settings or you won't be able to add the inputs and outputs as per the video.
You then just need to add the inputs and outputs you want from those available on your device. Studio one should give you a few basic ins and outs by default but I don't think it wire all your inputs up for you. You can name each input as you add them to make it easier when setting up projects in the future e.g. Kick, Snare, Overhead Left etc.
You can then add some audio tracks for the drum tracks then just select the inputs you configured for each track in the Studio One mix view (you just click on the name of the input (above the fader) and a list pops up allowing you to change it.