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