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