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