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