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