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