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