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