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)(17,19)(18,23)(22,24)(25,26,30,32)(27,35,37,31)(28,38,39,33)(29,34,40,36)(1,2)(3,7)(4,5)(6,8)(9,10)(11,17)(12,20)(13,14)(15,19)(16,21)(18,22)(23,24)(25,27,30,37)(26,31,32,35)(28,34,39,36)(29,33,40,38)(2,5)(6,7)(10,14)(15,17)(16,20)(22,23)(26,32)(29,40)(31,35)(33,38) involution — undirected(2,5)(6,7)(9,11,13,19)(10,15,14,17)(12,18,21,24)(16,22,20,23)(25,28,30,39)(26,33,32,38)(27,36,37,34)(29,35,40,31)(1,2)(3,6)(4,5)(7,8)(9,10)(11,15)(12,16)(13,14)(17,19)(18,22)(20,21)(23,24)(25,29)(26,34)(27,33)(28,35)(30,40)(31,39)(32,36)(37,38) involution — undirected(1,3)(2,6)(4,8)(5,7)(9,12,13,21)(10,16,14,20)(11,18,19,24)(15,22,17,23)(25,27)(26,31)(28,36)(29,33)(30,37)(32,35)(34,39)(38,40)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.