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