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