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