One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,5)(4,6)(7,8)(9,10,15,20)(11,21,23,36)(12,25,27,35)(13,19,14,18)(16,30,32,24)(17,28,34,29)(22,33,26,31)(37,40,39,38)(1,3)(2,5)(4,7)(6,8)(9,11)(10,16)(12,26)(13,30)(14,24)(15,23)(17,33)(18,36)(19,21)(20,32)(22,27)(25,39)(28,38)(29,40)(31,34)(35,37) involution — undirected(5,8)(9,12,13,28,15,27,14,29)(10,17,18,35,20,34,19,25)(11,22,24,38,23,26,30,40)(16,31,21,37,32,33,36,39)(11,23)(12,27)(16,32)(17,34)(21,36)(24,30)(25,35)(28,29) involution — undirectedA 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.