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