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