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