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