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