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