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)(15,24)(16,21)(17,22)(18,27)(19,23)(20,26)(25,28)(1,2)(3,4)(5,7,8,12)(6,9,10,11)(13,15,19,16)(14,20,23,28)(17,26,18,25)(21,27,24,22)(2,4)(5,6)(7,9)(8,10)(11,12)(13,16,19,15)(14,21,23,24)(17,26,18,25)(20,27,28,22)(5,7)(6,9)(8,12)(10,11)(13,17)(15,25)(16,26)(18,19)(20,28)(22,27) 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.