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