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