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