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