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