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