Standard Lumatone mapping for Pythagorean
The standard Lumatone mapping for Pythagorean-like scale systems has a C on the middle of the 5 keys sticking out the very left side of the keyboard, and the C major scale goes horizontally across the keyboard from there. The whole tone goes right-and-slightly-up and the diatonic semitone goes right-and-down, which implies that the apotome (the amount by which ♯/♭ alter pitches) goes up-and-slightly-right.
The name for this general kind of mapping is the Bosanquet-Wilson layout.
This mapping can be used without alteration for any rank-2 system whose period is an octave and whose generator is a (perhaps tempered) fourth or fifth. This includes Pythagorean, meantone, superpyth, helmholtz, etc. It will provide complete coverage for any edo up to 56 which has a single circle of 5ths, and many multi-ring edos can still be made to work with it by using a non-patent val as long as the generator forms a 5L 2s or 2L 5s mos scale.
Not all notes with four or more flats are shown here; they follow the obvious pattern.