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