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