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