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