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