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