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