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