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