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