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