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