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