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