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