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