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