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