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