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