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