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