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