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)(11,21)(12,27)(13,30)(14,19)(15,20)(16,29)(17,23)(18,31)(22,35)(24,40)(25,36)(26,37)(28,34)(32,38)(33,39)(2,5)(6,7)(9,11,14,23)(10,17,19,21)(12,28,29,40)(13,22,31,26)(15,33,32,25)(16,34,27,24)(18,35,30,37)(20,36,38,39)(9,12,27,10,13,20,32,18,14,29,16,19,31,38,15,30)(11,17,33,28,26,37,34,39,23,21,25,40,22,35,24,36)(1,3,4,8)(2,6,5,7)(9,13,14,31)(10,18,19,30)(11,22,23,26)(12,20,29,38)(15,27,32,16)(17,35,21,37)(24,25,34,33)(28,36,40,39)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.