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