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