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