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