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