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