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