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