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