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