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