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)(11,20)(12,17)(13,18)(14,27)(15,19)(16,21)(22,37)(23,30)(24,33)(25,40)(26,35)(28,32)(29,36)(31,38)(34,39)(9,11,15,23)(10,16,19,32)(12,21,14,28)(13,25,26,38)(17,30,27,20)(18,34,35,37)(22,29,39,24)(31,33,40,36)(2,4)(9,12,15,14)(10,17,19,27)(11,21,23,28)(13,24,26,29)(16,30,32,20)(18,33,35,36)(22,38,39,25)(31,34,40,37)(9,13,15,26)(10,18,19,35)(11,22,23,39)(12,24,14,29)(16,31,32,40)(17,33,27,36)(20,37,30,34)(21,38,28,25)(5,7,8,6)(10,19)(11,23)(17,27)(18,35)(21,28)(22,39)(25,38)(33,36)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.