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