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