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