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