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