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