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