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