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