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