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