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