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