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