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