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