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