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