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