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