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