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