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