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