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