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)(11,17)(12,15)(13,16)(14,19)(18,23)(20,22)(21,24)(25,26,29,34,30,35,38,39)(27,33,37,40,28,31,36,32)(1,3,5,8)(2,6,4,7)(9,10)(11,17)(12,15)(13,16)(14,19)(18,23)(20,22)(21,24)(25,27,30,28)(26,31,35,33)(29,37,38,36)(32,39,40,34)(9,11,13,19)(10,14,16,17)(12,20,21,18)(15,23,24,22)(25,27,30,28)(26,32,35,40)(29,36,38,37)(31,39,33,34)(1,2,5,4)(3,7,8,6)(9,12,13,21)(10,15,16,24)(11,18,19,20)(14,22,17,23)(25,28,30,27)(26,33,35,31)(29,36,38,37)(32,34,40,39)(1,4,5,2)(3,7,8,6)(10,16)(14,17)(15,24)(22,23)(25,29,30,38)(26,34,35,39)(27,36,28,37)(31,40,33,32)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.