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