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