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