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