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