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