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