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