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