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