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