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