I experimented with the same mind map. On the right I add the images.
Treemm2mm2p Note that I have numbered the last element in group. This way through repetition I know how many elements there are and always practice counting them in the same order (beneficial for memory). mm3mm3p More colors is more beneficial. The more center the more eye-catching the color is. Also, too much numbers is distracting, enough is just the last one.
Schematicmm4mm4p Geometric shapes allow you to grasp how many elements there are. Also good for memory. mm5mm5p Different colors (I am half red-colorblind, that's why I like blue more. Don't know about you. If you also like blue more then it's just that combination of black&blue is better than black&red). mm6mm6p This illustrates how much difference it makes whether the map is made with care or not.
Geometricmm7mm7p Quite good, I think. In this case every word is inside geometric shape. mm8mm8p Too tight. Geometric shapes overlap.
ConclusionMy favourite was: mm4p Although I think this was also very good: mm3p
What I learned:
Making with care, adding images, geometric shapes and various colors - these are what make mind map user friendly.