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