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