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