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