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