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