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