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