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)(11,18)(12,16)(13,22)(14,17)(15,20)(19,23)(21,24)(25,26,29,33,30,34,28,31)(27,32,35,39,37,40,36,38)(2,5)(6,7)(9,11,13,20,14,21,12,19)(10,15,16,18,17,23,22,24)(26,31,34,33)(32,38,40,39)(1,3,4,8)(2,6,5,7)(25,27)(26,32)(28,36)(29,35)(30,37)(31,38)(33,39)(34,40)(9,12,14,13)(10,16,17,22)(11,19,21,20)(15,18,23,24)(25,28,30,29)(26,31,34,33)(27,35,37,36)(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.