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