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