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