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