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)(15,18)(16,23,24,19)(17,20)(21,27,28,25)(22,26)(1,2,3,4)(13,15)(14,18)(16,21)(17,22)(19,25)(20,26)(23,27)(24,28)(6,9)(7,12)(10,11)(13,16)(14,19)(15,21)(17,24)(18,25)(20,23)(22,28)(26,27) involution — undirected(6,10)(9,11)(14,20)(15,22)(19,23)(21,28) 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.