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