One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,6,8,5)(4,7)(9,10,14,20,15,19,13,18)(11,21,24,16,25,33,23,32)(12,26,28,36,29,17,30,35)(22,38,39,31,27,37,40,34)(1,3)(2,5)(4,8)(6,7)(9,11,15,25)(10,16,19,32)(12,27,29,22)(13,24,14,23)(17,34,26,31)(18,33,20,21)(28,39,30,40)(35,37,36,38)(1,3)(2,6,7,5)(4,8)(9,12,13,28,15,29,14,30)(10,17,18,35,19,26,20,36)(11,22,23,39,25,27,24,40)(16,31,21,37,32,34,33,38)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.