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)(15,22)(16,19)(21,26)(23,24)(25,28)(5,7)(6,9)(8,11)(10,12)(13,14,19,26,17,21,16,18)(15,20,22,28,24,27,23,25)(7,11)(9,12)(13,15)(14,20)(16,23)(17,24)(18,25)(19,22)(21,27)(26,28) involution — undirected(2,4)(14,21)(18,26)(20,27)(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.