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