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