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