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