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