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