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)(11,14)(12,15)(13,16)(17,21)(18,22)(19,23)(20,24)(25,26,32,29)(27,37,40,28)(30,36,31,35)(33,39,38,34)(1,3,5,4)(2,6,8,7)(9,11)(10,14)(12,19)(13,17)(15,23)(16,21)(18,20)(22,24)(25,27,31,39,32,40,30,34)(26,33,36,28,29,38,35,37)(1,3,5,4)(2,7,8,6)(11,17)(14,21)(18,19)(22,23)(25,28,30,33,32,37,31,38)(26,34,35,40,29,39,36,27)(9,12,13,20)(10,15,16,24)(11,18,17,19)(14,22,21,23)(25,29,32,26)(27,38,40,33)(28,39,37,34)(30,36,31,35)(1,4,5,3)(2,6,8,7)(10,16)(14,21)(15,24)(22,23)(26,29)(28,37)(33,38)(35,36)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.