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