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