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