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