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)(13,14,19,21)(15,22,25,17)(16,18,26,20)(23,28,27,24)(1,2,4,3)(5,7)(6,9)(8,11)(10,12)(13,15,19,25)(14,17,21,22)(16,23,26,27)(18,24,20,28)(6,10)(7,11)(13,16)(14,18)(15,23)(17,24)(19,26)(20,21)(22,28)(25,27) involution — undirected(6,10)(9,12)(13,17,20,27,19,22,18,23)(14,15,16,24,21,25,26,28)(1,3,4,2)(13,18,19,20)(14,16,21,26)(15,24,25,28)(17,23,22,27)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.