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