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