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