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