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