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