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