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