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