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