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