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