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