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