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