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