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