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