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