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