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