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