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