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