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