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