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