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