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