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