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