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