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