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