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