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