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