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