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