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