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