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