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)(13,14,17,20)(15,22,24,27)(16,19,25,21)(18,26,28,23)(5,7)(6,9)(8,12)(10,11)(13,14)(15,18)(16,21)(17,20)(19,25)(22,23)(24,28)(26,27) involution — undirected(6,10)(9,11)(13,15,16,23,17,24,25,26)(14,18,21,22,20,28,19,27)(7,12)(9,11)(13,16,17,25)(14,19,20,21)(15,23,24,26)(18,27,28,22)(1,3,4,2)(6,10)(9,11)(14,20)(18,28)(19,21)(22,27)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.