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