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