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