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