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