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