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