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