I like the way you've represented the planes so far, but I think a few more things might give it a better feel and artistic touch.

I'd try having a sun and moon (splitting the image with day and night )on opposite sides (top/bottom) and maybe some sort of arrow or sign showing movement/rotation.
Then I'd use some sort of texture mixed with hand drawn elements on each of the planes surfaces.. maybe even go so far as to give them a bit of thickness too (making it a very thin cylinder).

To show a plane connected, have a solid colored line, those not connected have a dashed or dotted line branching off.
Where each branch is, above the plane I would show the deity or deities that reside or rule there.

I'd also try to show some sort of physical representation for each type of plane. As someone said earlier flames for fire.. etc etc.

Looks good so far.. don't think I was any help, but hope you continue your work!

Have some rep