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