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