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