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