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