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