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