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