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