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