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