One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,7)(3,4,8,6)(9,10,15,23,14,19,13,18)(11,16,22,24,12,21,20,17)(25,26)(27,33)(28,31)(29,32)(30,35)(34,40)(36,39)(37,38)(1,3,5,8)(2,6,7,4)(9,11,14,12)(10,16,19,21)(13,20,15,22)(17,23,24,18)(27,34)(29,36)(30,38)(32,39)(33,40)(35,37)(9,12,14,11)(10,17,19,24)(13,20,15,22)(16,23,21,18)(25,27,28,35)(26,30,31,33)(29,37,36,34)(32,40,39,38)(1,4,5,6)(2,3,7,8)(10,18)(13,15)(16,17)(19,23)(20,22)(21,24)(26,31)(30,33)(32,39)(38,40)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.