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