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