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