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