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