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