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