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