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