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