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