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