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