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