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