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