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