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