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