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