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