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