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