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