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