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)(11,21)(12,26,30,17)(13,20)(14,18)(15,19)(16,23)(22,37,39,34)(24,32)(25,33)(27,40,38,31)(28,35,29,36)(1,3)(2,5)(4,7)(6,8)(9,11,13,23,15,25,14,24)(10,16,18,21,19,32,20,33)(12,27,28,22,30,38,29,39)(17,34,35,31,26,37,36,40)(5,8)(9,12)(10,17)(11,22)(13,29)(14,28)(15,30)(16,31)(18,36)(19,26)(20,35)(21,34)(23,27)(24,38)(25,39)(32,40)(33,37) 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.