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