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