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