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