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