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