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