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