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