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