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