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