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