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