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