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