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