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