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