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