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