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