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