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