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