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