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