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)(15,21)(18,27)(22,28)(23,26)(2,3)(13,14)(15,22)(16,20)(17,25)(18,23)(19,24)(21,28)(26,27) involution — undirected(1,2,4,3)(6,9)(10,12)(13,15)(14,18)(16,21)(17,26)(19,28)(20,27)(22,25)(23,24)(1,3,4,2)(14,19)(17,24)(18,28)(20,25)(22,27)(23,26)(5,7,8,11)(6,10,9,12)(15,21)(18,27)(22,28)(23,26)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.