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