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