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