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)(15,21)(16,17)(18,20)(19,22)(23,26)(24,27)(25,28)(5,6)(7,11)(8,10)(9,12)(14,20)(16,22)(17,18)(21,27)(23,28)(24,26) involution — undirected(2,4)(5,7,8,12)(6,9,10,11)(13,15)(14,21)(16,23)(17,26)(18,24)(19,25)(20,27)(22,28)(7,12)(9,11)(13,16,19,20)(14,17,22,18)(15,23,25,27)(21,26,28,24)(6,10)(9,11)(13,17,19,18)(14,16,22,20)(15,24,25,26)(21,27,28,23)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.