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