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