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