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