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