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