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