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