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