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