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