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