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