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