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