(Before I say anything: is this an official transcription? I don't see any reason why you can't view the left hand as straight thirty-second notes and skip the five-let altogether. But for the actual answer...)
For five-lets, I recommend thinking "hip-po-pot-a-mus" throughout the beat.
On that first grouping, notice that it's a thirty-second-note tuplet preceded by a sixteenth-note rest. This means that the rest will take up two portions of the tuplet; the three thirty-second notes thus take up the "pot-a-mus" part of the beat.
This, in addition to the opening E, results in the following rhythm:
Hip Low E
This is made even more difficult by the fact that the next grouping is just regular thirty-second notes. I recommend putting a metronome on and making sure you can quickly switch between "hippotomas" and the thirty-second notes. Make sure all articulations within a beat are equal; the five-let will move more quickly than the thirty-second notes, but make sure you don't rush and finish your group of five early!