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