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