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