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