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