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