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