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)(15,24)(16,21)(17,19)(22,25)(26,27) involution — undirected(1,2)(3,4)(6,10)(11,12)(13,14)(15,16)(17,23)(18,20)(19,28)(21,22)(24,27)(25,26) involution — undirected(5,7,9,8)(6,11,10,12)(13,15,17,22,18,25,19,24)(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)(14,22,28,25,20,24,23,15)(6,10)(11,12)(13,17,18,19)(14,23,20,28)(15,22,25,24)(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.