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