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