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