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