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