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