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