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