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