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