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