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