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