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