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