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