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