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