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