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