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