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